The present invention relates to a process for preparing titanium or zirconium metal complexes in a reduced oxidation state. More particularly, the present process relates to a process for preparing such metal complexes containing hydrocarbyloxy substituents in a high yield, facile manner. The resulting metal complexes are used for polymerizing .alpha.-olefins including ethylene as well as vinylidene aromatic monomers, such as styrene. Generally the catalysts are activated for use by an activating cocatalyst such as an alkylaluminoxane or a cation forming compound. Such polymers may be usefully employed in the preparation of solid objects and articles such as a moldings, films, sheets and foamed objects by molding, casting or the like process.
In J. Am. Chem. Soc ., 3, 581 (1961) the preparation of cyclopentadienyltitanium dichloride by the reaction of diisobutyl aluminum chloride with biscyclopentadienyl titanium dichloride is disclosed. In Gmelin Handbuch der Anorganischen Chemie, Springer-Verlag, p 134, (1977), cyclopentadienyl titanium dihalides were stated to be prepared by reduction of the corresponding trihalide complexes using powdered zinc reducing agent in dry, oxygen free tetrahydrofuran.